Originally Posted by
DSJR
Good luck to him at nineteen or so electrolytics a side from memory ;)
By the mid 90's, caps had improved I think and I also believe Krell had *possibly* learned their lessons from earlier models which baked their amps hard continuously. If the voltage of the caps is a goodly margin over the voltages they need to deal with and they're not thermally stressed, it's my current belief that they shouldn't go off unduly in domestic use, and this particular amp had had an easy life as a secondary item, according to the chap who passed it to me. Always happy to be proved wrong though and that amp isn't the easiest to strip down and as it was working, no way would I needlessly ruin any value in it by attacking it with gusto. No hums or nasty noises (their transformers are SILENT too despite the size) and as far as I could ascertain, both channels 'sounded' the same and the bias lamps worked together, so I assume the amp was behaving itself.
I also believe it depends on the make of caps used. The very old US amps I use a lot originally had sealed caps which appear to have a very long life. the chunky looking alternatives they went over to in the mid 70's don't seem as long lived, despite showing no external issues - I'm about to experiment with one of my preamps from this firm, as the particular phono stage has a slight background high pitched 'hum' not noticed in the other one, which is reminiscent to me of a failing supply cap and this preamp sample has had a hard life in storage as well as much use when it was newer.